A series of 60 gastroplasty operations based on Mason's vertical banded procedure are described. Details of technique, modifications, complications and results are discussed. Operative treatment results in a reduction to within 40 per cent of ideal weight in 80 per cent of patients between 12 and 18 months after surgery. The constricting band should not be greater than 5 cm; if it is most procedures will fail after 18 months. Pouch size should be measured and made no greater than 20 ml. The importance of nutritional counselling is emphasized. The surgical treatment should form part of a multidisciplinary approach with careful selection and long-term follow-up.